Refillable fuse-cartridge.



J. T. DUGGEH.

REFILLABLE FUSE CARTRIDGE.

APPLICATION FILED JULY 30.1915.

1,243,719, Patented 0615.231917'.

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JESSE T. DUGGER, OF CHATTANOGA, TENNESSEE.

BEFILLAIBLE FUSE-CARTRXDGE.

Specification of Letters Patent.

Patented Get.. 23, 1917.

Application led. July 30, 1915. Serial No. 42,724.

To all 4whom t may concern:

Be it known that l, JEssE T. DUGGER, a lcitizen of the United Stat/es, residing at Chattanooga, in the4 county of Hamilton and State of Tennessee, have invented certain new and useful lmprovements in Reiillable Fuse-Cartridges, of which the following is a full, clear, and exact specification.

My invention relates to va reillable fuse cartridge of that type used in connection with electric circuits to interrupt the circuit, when it becomes overloaded in any manner, and thereby prevent damage to expensive electrical apparatus included in the circuit.

It is customary, in electric circuits, to employ a fuse cartridgeof the above mentioned character, which embodies a fusible element which, when the circuit becomes overloaded due to taxing it beyond its rated capacity, will blow7 or fuse out, and thereby interrupt the circuit until the fuse cartridge is replaced. Many types of fuse cartridges are on the market at the present day, and a majority of these are of that type in which the fusible conducting element is' not replaceable, and thus when the fuse blows the entire-cartridge must be replaced, and the shell, the most expensive part 0f the fuse cartridge, is thrown away, simply because f the lfusible element cannot be replaced. A few types of rellable fuse cartridges are on the market also, but these are of expensive construction due to the fact that they consist of numerous parts, and they are also so complicated that an lneXperienced person cannot readily replace the fusible element, and therefore their use is limited. p

One of the objects of my inventionlresides in the construction of a fuse cartridge of the refllable type, in which the parts are so assembledthat the fusible element,when blown, may be easily replaced.

Another object of my invention-resides in the provision, in a refillable fuse cartridge, of a shell containing the fusible element, and removable means closing eachV end of the shell and acting to retain the fusible element in position.

A still further and very important` ob- -jectv resides in the provision of a bridge across .each end of the. shell and over which the ends .of the fusible element are bent and then secured in place by removable tion view of one forml of fuse constructed according to my invention, and most appropriately designated as the knife type,7 for reasons hereinafter set forth.

Fig. 2 is an end elevation view with the shell closing means removed to show the end of the fusible element bent over the bridge.

Fig. 3 is an end elevation of the shell closing means.

Fig. 4 is anelevation view of one end of the type of fusible element employed in the fuse cartridge shown in Fig. 1.

Fig. 5 is a horizontal longitudinal section view of another form of fuse constructed according to my invention.

Fig. 6 is an end elevation of the fuse shown in Fig. 5 with the shell closing means removed to show the manner in which the end of the fusible element is bent over the bridge.

Fig. 7 is an end elevation View of the shell closing means used in the form shown in Fig. 5.

Fig. 8 is an elevation view of one end of the type of fusible element employed in the fuse cartridge shown in Fig. 5.

ln detail:

With particular reference to that type of cartridge illustrated in Fig. 1 and those parts thereof which are shown in Figs. 2 to 4 inclusive, the fuse cartridge comprises a cylindrical shell 1 of non-conducting material such as ber or the like, which is open at both ends. Over each open end of the shell 1 and resting on the edges thereof is a bridge 2 having oppositely threaded apertures 3. These bridges are held in place by ferrules 4 forced onto the ends of the shell 1 and provided with inwardly extending lips 5 for engagement with the bridges 2 to retain the same in position. The ferrules are secured to the shell 1 by rivets 6.

The fusible element 7 is of any well knowrv l type and is made of any suitable fusible material such as employed for this purpose; it is further provided with restricted ends 8 of suliicient length to be bent over bridges 2. ln order to retain the fusible element in position, shell closing means are provided which consist of circular cap pieces 9 provided with countersunk apertures 10 to aline with threaded apertures 3, and which receive screws 11 which hold the cap pieces inl position to close the ends of the shell l, and to clamp the ends of the fusible element 7 between bridges 2 and cap pieces 9.

In this form, preferably known as the knife form, each cap piece 9 carries a blade connection 9 for insertion between spring members, notshown, which engage the blade 9 and forms a connection which holds the cartridge in position.

Regarding the form of refillable fuse cartridge illustrated in Fig. 5 and the parts thereof shown in Figs. 6to 8 inclusive, the construction of the shell and ferrules is identical with the form shown in Fig. 1, but the bridges, cap pieces and fusible element are of diderent construction.

`ln this form, each bridge 12 is held in position by a ferrule provided with but a single threaded aperture 13, and the cap pieces 14 are provided with correspponding countersunlr apertures 15 to receive the screws 16 which hold the cap pieces in position to close the ends of the shell, and to clamp the ends 17 of the fusible element 18.

4The ends 17 of the fusible element 18 are bifurcated as shown, so as to slip over the 'shank of the screws 16 which hold cap pieces 14 in position and clamp the said ends between bridges 12-and the said cap pieces.

lt will be evident that, in order to remove a ruptured or blown fusible element in either type herein described, it is only necessary to remove the screws holding the cap pieces, whence the cap pieces may then be removed and the destroyed fusible element taken out and replaced by a new one without diliiculty, and thus the same cartridge shell may be used continuously.

ln this form, preferably known as the ferrule form, each ferrule isinserted between yieldable spring lingers which engage the ferrules to form a connection which holds the cartridge in position.

mesma While l have herein described certain specific embodiments of my invention which l know to be of practical construction, it is to be understood that l do not limit myself to these specific embodiments, except so far as the claims import.

I claim:

1. A rellable electric fuse cartridge comprising a cylindrical shell, bridges formed of narrow strips of metal resting upon the ends of said shell and providin spaces between the opposite edges of saidridges and the interior of the shell, vferrules permanently secured to the ends of said shell and provided with interior annular shoulders which engage and clamp said bridges to the shell, a fusible conducting element located within said shell and having its ends extending through certain of the spaces between the bridges and the interior of the shell and bent over upon said bridges, and removable means for clamping the ends of the fusible element to said bridges.

2. A relillable electric fuse cartridge comprising a cylindrical shell, bridges formed of narrow strips of metal resting upon the ends of said shell and providing spaces between the opposite edges of said bridges and the interior of the shell, ferrules permanently secured to the ends of said shell and provided with interior annular shoulders which engage and clamp said bridges to the shell, a fusible conducting element located within said shell and having its ends extending through certain of the spaces between the bridges and the interior of the shell and bent over upon said bridges, and a plurality of screw threaded apertures provided in each bridge and arranged on opposite sides of the bent ends of the fusible element, caps provided with knife terminals resting upon the bent ends of said fusible element and screws passing through apertures in said caps and engaging the screw threaded apertures of the bridges.

ln testimony whereof l have signed this specification in the presence of two subscribing witnesses.

JESSE T. DUGGER.

Witnesses E. A. Vlnrenr, PHILIP lil'. 

